Impact of energy turnover on fat balance in healthy young men during energy balance, caloric restriction and overfeeding.

Body weight control is thought to be improved when physical activity and energy intake are both high (high energy turnover). The aim of this study was to investigate the short-term impact of energy turnover (ET) on fat balance during zero energy balance, caloric restriction and overfeeding. In a randomized crossover study, 9 healthy men (BMI: 23.0 ±2.1 kg/m2, 26.6 ±3.5 y) passed 3x3 days in a metabolic chamber: 3 levels of ET (low, medium and high; physical activity level = 1.3-1.4, 1.5-1.6 and 1.7-1.8) were performed at zero energy balance (EB), caloric restriction (CR), and overfeeding (OF) (100%, 75%, 125% of individual energy requirement). Different levels of ET were obtained by walking (4 km/h) on a treadmill (0, 165, 330 min). 24-h macronutrient oxidation and relative macronutrient balance (oxidation relative to intake) were calculated and free fatty acids, 24-h insulin and catecholamine secretion were analyzed as determinants of fat oxidation. During EB and OF, 24-h fat oxidation increased with higher ET. This resulted in a higher relative fat balance at medium ET (EB: +17%, OF: +14%) and high ET (EB: +23%, OF: +17%) compared to low ET (all p<0.05). In contrast, CR led to a stimulation of 24-h fat oxidation irrespective of ET (no differences in relative fat balance between ET levels, p>0.05). In conclusion, under highly controlled conditions a higher energy turnover improved relative fat balance in young healthy men during overfeeding and energy balance compared to a sedentary state.

RCT Entities:   Population Interventions Outcomes